1. Field of the Invention
The present invention relates to apparatus for restricting access to the electrically charged components within metal-enclosed switchgear, and more particularly, the present invention relates to apparatus for restricting access to metal-enclosed switchgear until a tool for opening a switch to isolate a high voltage fuse and remove the fuse is properly positioned.
2. Description of the Prior Art
The present invention constitutes an improvement over the structure disclosed in U.S. Pat. No. 3,842,381 -- Bernatt et al. entitled "INTEGRAL FUSE AND SWITCH SUPPORT FOR METAL-ENCLOSED SWITCHGEAR", issued Oct. 15, 1974, and assigned to the same assignee as the present invention. That patent illustrates one type of prior art metal-enclosed loop switchgear. Metal-enclosed pad-mounted switchgear for distribution of electric power is employed for switching load circuits and for interrupting and isolating faults. The overall size of the enclosure is important since the size must be consistent with proper spacing between energized elements and between energized elements and ground. A compact construction efficiently utilizing the space within the metal enclosure is of paramount importance.
Further, since it is desirable to selectively isolate a fuse from its respective supply circuit so that the fuse can be tested and/or replaced without opening the loop circuit, it is desirable to provide isolator switches between the supply circuit and the fuse to interrupt current flow to the electrical load. Since the distance between the components within metal-enclosed switchgear is quite limited, accidental contact with the charged portions of the circuitry is possible unless safeguards are provided. Accordingly, it is desirable to provide a means for removing the fuses from the metal enclosure which permits the seviceman to do so without coming into contact with or into proximity to the electrically charged components of the switchgear.
In addition, since vandals and curious children sometimes break into and open the covering doors of metal-enclosed switchgear, it is desirable to restrict access to the electrically charged components of the switchgear to prevent accidental shock.